Spinosaurus
Spinosaurus (meaning "spine lizard"Creisler, B. (7 July 2003). "Dinosauria Translation and Pronunciation Guide S". Retrieved 3 September 2010. (Note: Site no longer online.) is a spinosaurid theropod dinosaur that lived in Cretaceous Africa. It has become well known due to its size and recognizable shape. It lived near lakes and rivers. Description Several features make Spinosaurus one of the most recognizable dinosaurs in the modern world. Size Spinosaurus has always been one of the longest dinosaurs. Early estimates put its length at around 15 meters (49 feet)von Huene, F.R. (1926). "The carnivorous saurischia in the Jura and Cretaceous formations principally in Europe". Rev. Mus. La Plata 29: 35–167. and 4 tonnesPaul, G.S. (1988). "Family Spinosauridae". Predatory Dinosaurs of the World. New York: Simon & Schuster. pp. 271–274. ISBN 0-671-61946-2., but later estimates have ranged from 12 to 18 meters and from 7 to nearly 21 tonnes.Therrien, F.; and Henderson, D.M. (2007). "My theropod is bigger than yours...or not: estimating body size from skull length in theropods". Journal of Vertebrate Paleontology 27 (1): 108–115. doi:10.1671/0272-4634(2007)27108:MTIBTY2.0.CO;2. ISSN 0272-4634. Spines The most distinctive feature of the aptly-named Spinosaurus is its spines. These neural spines were part of the vertebrae and were somewhat similar to the spines on Dimetrodon (which was not a dinosaur) and Ouranosaurus (which was a contemporary of SpinosaurusPalmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 144. ISBN 1-84028-152-9.). These spines probably supported a large sail (see Sail function, below). Some believe, however, that they in fact supported a large hump.Bailey, J.B. (1997). "Neural spine elongation in dinosaurs: sailbacks or buffalo-backs?". Journal of Paleontology 71 (6): 1124–1146. JSTOR 1306608. Skull Like other spinosaurids, Spinosaurus had an elongated snout filled with straight, conical teeth.Dal Sasso, C.; Maganuco, S.; Buffetaut, E.; and Mendez, M.A. (2005). "New information on the skull of the enigmatic theropod Spinosaurus, with remarks on its sizes and affinities". Journal of Vertebrate Paleontology 25 (4): 888–896. doi:10.1671/0272-4634(2005)0250888:NIOTSO2.0.CO;2. ISSN 0272-4634. Like the size of the animal itself, the size of its skull is debated. Comparing it with the skull of its close relative Irritator, Dal Sasso and colleagues gave the length of the Spinosaurus skull at 1.75 meters (5.7 feet). However, since the shapes of spinosaurid skulls can vary and not many are found complete to start with, this length might not be correct. Classification Spinosaurus gives its name to the family Spinosauridae. It is also part of the family Spinosaurinae, which also includes Irritator and Oxalaia from Brazil. They are distinguished from other spinosaurid subfamilies by possessing straight, unserrated teeth.Holtz, T.R., Jr.; Molnar, R.E.; and Currie, P.J. (2004). "Basal Tetanurae". In Weishampel, D.B.; Dodson, P.; and Osmólska, H. (eds.). The Dinosauria (2nd ed.). University of California Press. pp. 71–110. ISBN 978-0-520-25408-4. History In 1910, a paleontological expedition led by Ernst Stromer arrived in Egypt. Stromer was intent on finding early mammals in the desert; namely, primates and hominids. Every single site they dug consistently revealed amazing reptile fossils, but no mammals. In 1912, Stromer was back in Germany, disappointed to have found no mammals, but his colleague Richard Markgraf discovered a partial skeleton of a meat-eating dinosaur. Stromer received the bones and in 1915 named them Spinosaurus aegypticus.Stromer, E. (1915). "Ergebnisse der Forschungsreisen Prof. E. Stromers in den Wüsten Ägyptens. II. Wirbeltier-Reste der Baharije-Stufe (unterstes Cenoman). 3. Das Original des Theropoden Spinosaurus aegyptiacus nov. gen., nov. spec" (in German). Abhandlungen der Königlich Bayerischen Akademie der Wissenschaften, Mathematisch-physikalische Klasse 28 (3): 1–32.Nothdurft, William and Smith, Josh. Book. The Lost Dinosaurs of Egypt. Cosmos Studios, New York. 2002.A Tribute to Ernst Stromer: Hundred Years of the Discovery of Spinosaurus aegypticus: Saubhik Ghosh: EKDIN, 11 and 12 July 2011 (www.ekdin.org) Additional remains believed to be of Spinosaurus were uncovered in 1934 and described by Stromer. However, it is believed today that these are in fact a different dinosaur, perhaps Carcharodontosaurus.Stromer, E. (1934). "Ergebnisse der Forschungsreisen Prof. E. Stromers in den Wüsten Ägyptens. II. Wirbeltier-Reste der Baharije-Stufe (unterstes Cenoman). 13. Dinosauria" (in German). Abhandlungen der Bayerischen Akademie der Wissenschaften Mathematisch-naturwissenschaftliche Abteilung, Neue Folge 22: 1–79.Sereno, P.C.; Beck, A.L.; Dutheil, D.B.; Gado, B.; Larsson, H.C.E.; Lyon, G.H.; Marcot, J.D.; Rauhut, O.W.M.; Sadleir, R.W.; Sidor, C.A.; Varricchio, D.D.; Wilson, G.P; and Wilson, J.A. (1998). "A long-snouted predatory dinosaur from Africa and the evolution of spinosaurids". Science 282 (5392): 1298–1302. Bibcode 1998Sci...282.1298S. doi:10.1126/science.282.5392.1298. PMID 9812890. The original Spinosaurus specimens were actually destroyed in 1944 during the middle of World War II, in a British bombing raid on Munich, where the fossils were stored.Smith, J.B.; Lamanna, M.C.; Mayr, H.; and Lacovara, K.J. (2006). "New information regarding the holotype of Spinosaurus aegyptiacus Stromer, 1915". Journal of Paleontology 80 (2): 400–406. doi:10.1666/0022-3360(2006)0800400:NIRTHO2.0.CO;2. ISSN 0022-3360. However, new material has been recovered since then. There is currently one accepted species, along with a second, S. maroccanus, although its status as a proper species is currently uncertain.Russell, D.A. (1996). "Isolated dinosaur bones from the Middle Cretaceous of the Tafilalt, Morocco". Bulletin du Muséum National d'Histoire Naturelle, Paris, 4e série, section C 18 (2–3): 349–402. Paleoecology The North African environment in which Spinosaurus lived was similar to modern mangrove forests.Sereno, P.C.; Dutheil, D.B.; Larochene, M.; Larsson, H.C.E.; Lyon, G.H.; Magwene, P.M.; Sidor, C.A.; Varricchio, D.J.; and Wilson, J.A. (1996). "Predatory dinosaurs from the Sahara and Late Cretaceous faunal differentiation". Science 272 (5264): 986–991. Bibcode:1996Sci...272..986S. doi:10.1126/science.272.5264.986. JSTOR 2889583. PMID 8662584. Other dinosaurs that lived in that time and place include titanosaurid sauropods, primitive hadrosaurs, and a wide variety of other large theropods.Smith, J.B.; Lamanna, M.C.; Lacovara, K.J.; Dodson, P.; Smith, J.R.; Poole, J.C.; Giegengack, R.; and Attia, Y. (2001). "A giant sauropod dinosaur from an Upper Cretaceous mangrove deposit in Egypt". Science 292 (5522): 1704–1706. Bibcode:2001Sci...292.1704S. doi:10.1126/science.1060561. PMID 11387472. Paleobiology Sail function What the sail (or hump) on the back of Spinosaurus was for is not known with certainty, although there have been many theories. It may have served a thermoregulatory function, warming up the dinosaur's body in the early morning for extra energy.Halstead, L.B. (1975). The Evolution and Ecology of the Dinosaurs. London: Eurobook Limited. pp. 1–116. ISBN 0856540188. The sail also could have been used for display, or possibly a variety of different functions. Diet Spinosaurus clearly ate fish, its conical teeth well suited to grabbing the slippery prey. the evidence of this is that they have been found with fish material in their stomachs.Charig, A.J.; and Milner, A.C. (1997). "Baryonyx walkeri, a fish-eating dinosaur from the Wealden of Surrey". Bulletin of the Natural History Museum, Geology Series 53: 11–70. but Greg Paul has stated that Spinosaurus was probably opportunistic, preferring fish but not hesitating to take land prey such as other dinosaurs. In 2010, an isotope analysis of Spinosaurus teeth showed the oxygen isotope ratios present indicate the animal may have had a semiaquatic lifestyle, supporting the possibility that it had a diet of mainly fish.Amiot, R.; Buffetaut, E.; Lécuyer, C.; Wang, X.; Boudad, L.; Ding, Z.; Fourel, F.; Hutt, S.; Martineau, F.; Medeiros, A.; Mo, J.; Simon, L.; Suteethorn, V.; Sweetman, S.; Tong, H.; Zhang, F.; and Zhou, Z. (2010). "Oxygen isotope evidence for semi-aquatic habits among spinosaurid theropods". Geology 38 (2): 139–142. doi:10.1130/G30402.1. Posture Although Spinosaurus has usually been depicted as bipedal, it has been suggested since the 1970s that it was at least partially bipedal. Both its robust arms and weight of the sail support this theoryGlut, D.F. (2000). "Spinosaurus". Dinosaurs: The Encyclopedia. 1st Supplement. Jefferson, North Carolina: McFarland & Company, Inc. pp. 329–333. ISBN 0-7864-0591-0., although the idea that spinosaurids were entirely quadrupedal no longer exists. Even though theropods could not pronate their handsCarpenter, K. (2002). "Forelimb biomechanics of nonavian theropod dinosaurs in predation". Senckenbergiana Lethaea 82 (1): 59–76. doi:10.1007/BF03043773., quadrupedal locomotion would still be possible, as shown by Jurassic theropod tracks.Milner, A.R.C.; Harris, J.D.; Lockley, M.G.; Kirkland, J.I.; and Matthews, N.A. (2009). Harpending, Henry. ed. "Bird-like anatomy, posture, and behavior revealed by an Early Jurassic theropod dinosaur resting trace". PLoS ONE 4 (3): e4591. doi:10.1371/journal.pone.0004591. In popular culture One of the most famous appearances of Spinosaurus was in the 2001 film Jurassic Park III. In the film, a Spinosaurus fights a Tyrannosaurus and kills the creature by snapping its neck, replacing it as the main dinosaur.Chandler, G. (August 2001). "A bite-size guide to the dinosaurs of the new movie Jurassic Park III". National Geographic World. Reconstructions of Spinosaurus based on this appearance have since proliferated in a wide variety of media, including television series, books, and games. Spinosaurus had been depicted in many 20th century dinosaur books, although due to the lack of fossil material it usually had a head reminiscent of that of a tyrannosaur. It was sometimes even restored as being quadrupedal.Glut, D.F. (2000). "Spinosaurus". Dinosaurs: The Encyclopedia. 1st Supplement. Jefferson, North Carolina: McFarland & Company, Inc. pp. 329–333. ISBN 0-7864-0591-0. This was based on a skeletal reconstruction created in the 1950s.Lapparent, A.F. de; and Lavocat, R. (1955). "Dinosauriens." In: Piveteau, J., editor. Traité de Paléontologie. Tome V. La Sortie des Eaux. Naissance de la Tétrapodie. L'Exubérance de la Vie Végétative. La Conquête de l'Air. Amphibiens. Reptiles. Oiseaux. Paris: Masson et Cie, pp. 785-962. It has also featured on African postage stamps.Glut, D.F.; and Brett-Surman, M.K. (2000). "Dinosaurs and the media". In Farlow, J.O.; and Walters, R.H. The Complete Dinosaur. Bloomington, IN: Indiana University Press. pp. 673−706. ISBN 0-253-21313-4. Retrieved 12 September 2010. in planet dinosaur, a bbc documentary, spinosaurus is shown to eat fish, such as onchipristis. it, however, eats both fish and meat. it often had rivalry with Concavenator. many papo and shleich toys were made of it. References Category:Animals Category:Dinosaurs Category:Theropods Category:Carnivores Category:Fossil taxa described in 1915 Category:Piscivores